Electric-elevator control.



No. 784,869. PATENTED MARIM, 1905. N. 0. LINDSTROM. ELECTRIC ELEVATOR CONTROL.

YLPPLIUATION FILED NOV.17,-1904.

awom-foz pvi/tmcoow I I v as 21 51 532? J82 UNITED STATES Patented. March 14:, 1905.

PATENT EEIcE.

NlLS O. LIN DSTROM, OF JERSEY UlTY, NEW JERSEY, ASSlG N OR TO ALONZO B. SEE AND \YALTER L. TYLER, F NEW YORK, N. Y.

ELECTRIC-ELEVATOR CONTRQL.

SPECIFICATION forming part of Letters Patent No. 784,869, dated March 14:, 1905.

Application filed November 17, 1904. Serial No. 233,089.

To (0/1 mil/0. 77, [it nuty cancer/1,;

Be it known that I, NILs O.LINDSTROM, a citi- Zen of the United States, residing at Jersey City. in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Electric Elevator Control, of which the following is a full, clear, and exact description.

This invention relates to push-button-con- 1O trol systems. for electrically-operated elevators; and the primary object of the invention is to provide a control system by which persons desiring to use the elevator may operate it themselves without the aid of a special ele- 5 vator-man and may travel from floor to floor without liability of accident and without in tcrference between passengers already occupyingthe car and others that may endeavor to obtain the use of the car at the same time. For a perfectly safe system it is necessary that after one wouldbe passenger has pushed a button to bring the car to him another cannot interfere with the movements of the car in any manner until the first passenger has 5 obtained the car, movedthereon to his destined floor, passed out of the car, and finally closed the shaft-door behind him. If it is at all possible at any moment between the first push of the button and the final closing of the 3 door at the destined landing for another passenger to interefere with the car, the system is unsafe.

The invention herein described provides a perfectly safe system of push-button control. 3 5 In the accompanying drawing I have represented conventionally the apparatus and various circuits used in carrying out my invention.

The electric motor for moving the elevator 4 is indicated at M, of which R is a sectional resistance in the armature-circuit for graduating the start of the motor in the usual way. S is a solenoid having a core 8 attached to the rheo statarm r, so that when the solenoid is energized the resistance will be cut out of the armature-circuit and the motor permitted to gradually attain its highest speed. it will be understood that a dash-pot or any other contrivanee may be used in connection with this solenoid to retard the movement of its 5 core. The rheostat-arm is pivoted and carries an extension r, to which is affixed a blade adapted to engage two contacts 1 and 2 when the elevator is in its normal or unused condition.

t is a switclrlever arranged above the rheo stat-arm and pivoted in a position where it will be engaged by a roller or lug 0- on the core s when the latter is raised by the energizing of the solenoid S. The switch-lever 25 bears at one end against a contact 3, the opposite end of the lever being heavier in order to normally hold it in this position. \Vhen engaged by the roller r however, lever t is moved so that it will leave contact 3 andcon 5 nect with contact 4.

The regular up and down solenoids, whose function it is to close the main switch and direct current through the motor in a manner to send the car either up or down. as 7 required, are indicated by the words Up and Down. This apparatus and its mode of operation is well known in the art and forms no part of the present invention. The car is indicated by the dotted rectangle and contains one push-button for each floor of the building, as well as any other buttons, such as a stop-button for emergency, that may be desired. None of these latter, however, is shown. On each floor of the building or at each elevator-landing is placed a push-button, and these correspond, respectively, with the buttons in the car, they being connected in parallel circuit with each other and the cir euit-wires passing through a flexible cable in 8 5 the usual manner. The push-buttons at the landings are indicated by 1st floor, 2nd floor, 3rd floor, c. At each landing the door permitting access to the shaft operates a cut-out switch, indicated in the drawing by 9 Door-switch. These door-switches are all in series, so that one of them is all that need be shown in the drawing. The gate on the car itself, which is usually closed while the car is in motion, may also operate a cut-out switch, 9 5 indicated in the drawing by Gate-switch,

but as both the gate and the door are not always used we will consider only the switch connected with the landing-door. The doorswitch and the gate-switch are shown in the drawing as in series with each other, and it will be seen from the circuits hereinafter traced that they are also in series with the floor push-buttons and the corresponding car pushbuttons, while, as before explained, the car and floor buttons are in parallel with each other. There are also provided, corresponding to each floor, magnetic switches in, m, mi", &c., consisting of an electron'iagnet or solenoid whose armature carries a cross-head I), adapted to bridge two contacts p and 7), the function of these switches being to hold a given circuit closed after it has lirst been closed by hand at one of the push-buttons. In connection with this system .I use another piece of apparatus well known in the art as a regulater. ally near the motor and driven by it ataspeed corresponding' to or in proportion with that of the car. This regulator contains a series of switches, one for eachfloor of the building, and its function is to open the control-circuit whenever the car reaches a floor corresponding to a push-button that may have been operated by the'passenger. its function is also to set the switches at each floor as the car passes, so that the current will be sent through either the up or down solenoid, depending upon whether the car is above or below the floor to which it may be called. The switches on the regulator are inechanicallyoperated by cams, each switch for the intermediate landing consisting of a lever and a pair of contacts on each side of it. When the car arrives at a landing, the switch-lever is thrown to the midposition between both pairs of contacts and opens any circuit that may have been previously established through either pair of contacts. When the car moves upward from the landing, it throws the switch-lever to one side, closing the contacts that control thecircuit to the down solenoid, and after the car moves downward from a given floor the other pair of contacts is closed to complete the circuit when necessary through the up solenoid. \Vith this brief description of the regulator the operation of the system will be described and the circuits at the same time pointed out.

\Vith the parts in the position shown in the drawing the elevator-car is supposed to be standing at the top-floor landing, the switch in the regulator corresponding to the top floor being open and the switches corresponding to all other floors of the building (only one intermediate floor being shown) having been set in position to energize the down solenoid by the car in traveling upward to the top floor. Suppose a person on the first floor desires to be carried to the third floor. He will push the button 1st floor on the landing. This This is a frame or body mounted usuii tsetse will close the following circuit: from the positive main by wire through the doorswitch at the third-floor landing, wire (3, contacts 1 and 2, wire 7, wire 8, lirst-tloor landing push-button, wire 9, wire 10, switch-magnet m', wire 11, regulator-switch 1, wires 12 and 13, down solenoid, wire 1%, clips 18-of the up solenoid to the. negative main. This will energize switch-magnet m and the down solenoid. Magnet 11 will at once close a branch from the wire 5 by way of resistance 9 and wire 17 to the wire 10, so that when the passenger releases the push-button at the landing the circuit before traced through the switch-magnet m and the down solenoid will be maintained. The down solenoid being onergized, its core is lifted, the circuit through the up solenoid is broken at the clips [(3, and main circuit through the motor is closed through wires 19 2O 21, resistance h, resistance-arm w, and wire At the same time also a circuit is closed by the armature of the down solenoid through the solenoid S by way of wire 23, contact 3, switch-lever t, and wire 24. The motor will now start and lower the car, the core of solenoid S being lifted until all of the resistance is out of the armaturecircuit and the motor is operating at full speed. At the moment the core s lifts the manual control-circuit is broken at the con tacts 1 and 2 by the removal of the blade from contact with those clips, and at the upper end of the stroke of the solenoid-core the roller 1" strikes switch-lever if and throws it out of connection with contact 3 and into connection with contact a. The wire 23 therefore becomes dead, but the current continues to How through solenoid S by way of resistance and contact 4. Nhile the car is in motion it will be seen that another operation of any of the floor push-buttons will not in any manner interfere with the movement of the elevator, since the control-circuit 6 7 is open at the points 1 2. \Nhen the car reaches the lirst tloor, the regulator opens the circuit at the switch 1, thus deenergizing switch-magnet m and the down solenoid. The latter drops its armature and opens the motor-circuit,allowing the car to come to rest; but the core of solenoid S still remains up, because it is not now dependent upon the main switch actuated by the down solenoid.

' Hence the contacts 1 and 2 still remain open,

opens the circuit of solenoid S at the doorswitch, which permits the solenoid-core to fall and close the manual control-circuit at 1 2, and at the same time throw the resistance all into the armaturecircuit. On entering the car the passenger closes the landing-door, and thereby completes the control-circuit at all ICC points except at the push-buttons. He now pushes the third floor' button in the car and completes the following circuit: from the positive main by wires 5, 6, and 7, third-floor push-button in the car, wire 24, switch-magnet on, wire 25, regulator-switch 3, (which was closed automatically when the car left the third floor,) wires 26 and 27, up solenoid, wire 28, clips 16, wire 29, and wire 15 to the negative main. The motor then starts as before, the connections being such as to reverse its direction of rotation, so that the car will move upward, (these connections not being shown for the up solenoid in the drawing.) The car will proceed uninterruptedly as before until it reaches the third floor, where upon the switch in the regulator being automatically opened the Lip-solenoid circuit is de energized and the motor comes to a stop, leaving the core of solenoid S hanging up as be fore. No other would-be passenger can in the meantime stop or start the car by operating the buttons and the passenger is protected until he steps out onto the landing at the third floor, for in opening the door he disables the control-circuit at the door-switch, notwithstanding the fact that he at the same time permits the core of solenoid S to fall and close the control-circuit at contacts 12. Upon closing the door of the landing the car is then at the service of a person on any other landing, for the door then closes the door-switch and finally completes the control-circuit except at the push-buttons.

The novelty claimed for my invention resides in the construction and operation of the resistance-solenoid S, whereby its core is retained in its uppermost position after the motor is stopped, and the control-circuit is continued disabled at the contacts 1 and 2 until the passenger has opened and closed the landing-door. I am aware that the same result has been accomplished in other ways; but, so far as known to me, never with so simple apparatus as I have provided that is to say, I

use the resistance-solenoid for the doublepurpose of disabling the control-circuit and of controlling the starting resistance. This, in connection with the switch t for maintaining the current through the solenoid after it has been cut off from the motor, constitutes my invention.

The resistance Q is used to prevent heating of the solenoid S in case for any reason the elevator-door is not opened promptly.

It will be understood that the main switches operate the brake and any other of the usual circuits; but as these have nothing to do with the invention they are not shown.

Having described my invention, I claim 1. In an electric elevator, a-manually-operated control-circuit including a door-circuit breaker, a resistance-solenoid adapted to be thrown into circuit with said doorcircuit breaker, and itself adapted to control said manually-operated control-circuit.

2. In an electric elevator, the combination of a solenoid adapted to control the armature resistance and the elevator-control circuit, and two circuits both including said solenoid, one of which is closed and opened simultaneously with the closing and opening of the motorcircuit and the other of which includes a doorcircuit breaker.

3. In an electric elevator, the combination of a solenoid adapted to control the armature resistance on the elevator-control circuit, and two circuits both including said solenoid, one of which is closed and opened simultaneously with the closing and opening of the motor circuit and the other of which includes a doorcircuit breaker, and a switch adapted to throw the solenoid from one circuit to the other, substantially as described.

4. In an electric elevator, the combination of the car-motor, a rhcostat therefor, a solenoid adapted to operate the rheostat, a control-circuit common to all landings and adapted to be opened by said solenoid when it is energized to start the motor, and means for maintaining the solenoid energized after the motor is stopped.

55. In a push-button-control system for elevators, the combination of an electromagnet adapted to control the motor resistance, two circuits each including the resistance-magnet, one of said circuits being controlled by a motor-controlling switch and the other including a cut-out actuated simultaneously with the elevator-car door.

6. In an electric elevator, a motor, an armature-resistance solenoid, a main switch adapted to close the circuit through the motor and the solenoid simultaneously, an auxiliary switch actuated by the resistance-solenoid and adapted to direct current through the solenoid independently of the main switch, a manually operated control circuit and means whereby the resistance-solenoid will hold the control-circuit open while it is holding the auxiliary switch in a position to direct current through the solenoid.

In witness whereof I subscribe my signature in the presence of two witnesses.

NILS O. LINDSTRQM.

\Vitnesses:

FRANK S. OBER, N ALDO M. Unarm. 

